Error when running exports transformation with shadowed variable

[daveisfera]

This the stacktrace:

 ERR test.js Transformation error (Identifier 'ids' has already been declared (3:12))
SyntaxError: Identifier 'ids' has already been declared (3:12)
    at Object.raise (/Users/dlj/.config/yarn/global/node_modules/@babel/parser/lib/index.js:6322:17)
    at ScopeHandler.checkRedeclarationInScope (/Users/dlj/.config/yarn/global/node_modules/@babel/parser/lib/index.js:3754:12)
    at ScopeHandler.declareName (/Users/dlj/.config/yarn/global/node_modules/@babel/parser/lib/index.js:3720:12)
    at Object.checkLVal (/Users/dlj/.config/yarn/global/node_modules/@babel/parser/lib/index.js:8006:22)
    at Object.checkLVal (/Users/dlj/.config/yarn/global/node_modules/@babel/parser/lib/index.js:373:15)
    at Object.parseVarId (/Users/dlj/.config/yarn/global/node_modules/@babel/parser/lib/index.js:10441:10)
    at Object.parseVar (/Users/dlj/.config/yarn/global/node_modules/@babel/parser/lib/index.js:10412:12)
    at Object.parseVarStatement (/Users/dlj/.config/yarn/global/node_modules/@babel/parser/lib/index.js:10234:10)
    at Object.parseStatementContent (/Users/dlj/.config/yarn/global/node_modules/@babel/parser/lib/index.js:9830:21)
    at Object.parseStatement (/Users/dlj/.config/yarn/global/node_modules/@babel/parser/lib/index.js:9763:17)

And here's a simple file that demonstrates the issue:

class Repeated {
    doSomething(ids) { 
        let ids = { ids: ids.toString() };
        return ids;
    }
}

[xjamundx]

Thanks for the report. Which transform are you using?

[xjamundx]

FYI this is legitimately a syntax error:

function a(b) { let b; }

so probably we'll need to detect these cases somehow... 🤔

[xjamundx]

Oh was this var to let?

[dave-nm]

It was the exports transformation.